The existing navigation devices are disposed mainly in motor vehicles, such as, automobiles, trains or the like, and rarely in apparatuses related to bicycles. However, navigation is also needed for bicycles in long-distance riding. Among the existing technical solutions to navigation for bicycles, one is to send navigation information to a bicycle and project the navigation information ahead of the bicycle by an illuminating lamp disposed on the front end of bicycle, and another is to dispose a display device on a bicycle that receives and displays navigation information.
In both of the above-mentioned solutions, although navigation for bicycles can be achieved, the riders are distracted by viewing navigation information, easily leading to traffic accidents; it is even more inconvenient to use navigation in such ways when a plurality of riders are riding as a team.